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XXVI. On the Structure and Use of the Ligamentum Rotundum Uteri, with some 
observations upon the change which takes place in the Structure of the Uterus 
during Utero-gestation, By G. Rainey, 3I.R.C.S., Demonstrator of Anatomy at 
St. Thomas s Hospital. Communicated by Joseph Henry Green, Esq., F.R.S. 
Received January 15, — Read April 11, 1850. 
Prior to the discovery of the striated character of voluntary muscle, about 1765, 
by Fontana, physiologists were unacquainted with any certain mark by which they 
could distinguish this variety of muscle from many other structures ; and physiology 
being at that period in advance of anatomy, the question of the muscularity of many 
parts was obliged to be decided by their function instead of by their structure ; but 
in the present state of minute anatomy, improved as it has been of late by the 
researches of microscopists, physiology and anatomy are made to move more in paral- 
lelism ; this is especially the case with respect to the muscular system, so that if a 
muscle be made up of a bundle of fascicles of nearly equal size, and each one be 
marked transversely with parallel striae, it is known to act either directly in obedience 
to the will, or to be capable of being called into operation through excito-rnotory 
influence, whilst a muscle consisting merely of an aggregation of fibres more or less 
distinctly nucleated, is known to act independently of the will ; hence muscles are 
now named according to their function, voluntary and involuntary ; or according to 
their structure, striped and unstriped. In the class of striped muscles physiologists 
are agreed to place the voluntary muscles, the upper part of the human oesophagus, 
and the heart ; in that of unstriped ones, the muscular coat of the intestinal canal, 
the bladder, the uterus and round ligaments. As it respects the parts included in 
the latter division of this classification, I am obliged to dissent altogether in reference 
to the structure of the round ligaments of the uterus, having found in every subject 
in which I have examined them (the number being about a dozen) well-marked 
muscular fibres of the striped variety, in fact that they correspond in all respects to 
regular voluntary muscles : with this conviction I am desirous to communicate the 
result of my observations to the Royal Society. I may also add, that I have in my 
possession numerous preparations, microscopic as well as ordinary dissections, in 
which the accuracy of the facts stated in this paper are easily demonstrable. 
The so-called round ligament of the uterus, regarded as a muscle, may be said to 
ai'ise by three fasciculi of tendinous fibres ; the inner one from the tendon of the 
internal oblique and transversalis near to the symphysis pubis, the middle one from 
the superior column of the external abdominal ring near to its upper part, and the 
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